1. Field of the Invention
The present invention relates to a method of testing an assembly which is adapted to move through a cycle and more particularly, a method of testing an assembly by sensing the applied forces to effect movement of the assembly at various points in the cycle and utilizing the sensed information to determine whether the assembly meets predetermined quality standards.
Methods of testing completed assemblies, such as engines or motors, are well known in the art. These methods include the steps of operating the motors and and/or assembled parts to be tested while sensing such variables as starting torque, running torque, operating temperature, and electrical characteristics such as voltage and current in an effort to perform quality control operations on the assemblies. However, the known methods do not provide for determining running torque over a period of time, or reading the running torque differential. The determination of running torque over a time period allows a user to measure the bearing drag on items like four-cylinder engines by observing the low point on running torque. Additionally, by measuring differential torque a user can measure the piston ring draft directly.
2. Prior Art
The Eshghy U.S. Pat. No. 4,267,629 entitled Tension Control of Fasteners discloses a method for tensioning a threaded joint by sensing the torque utilized to tighten the joint over various angles of rotation of the nut. The Eshghy patent has not been utilized for quality control of mechanical assemblies other than threaded fasteners. The Brown et al U.S. Pat. No. 4,102,182 entitled Quality Checking System for a Thread Fastener Assembly also discloses an additional method of performing joint analysis by analyzing the torque angle signature of the joint as it is tightened. Brown does not disclose the quality control testing of a mechanical assembly.